// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_MEDIA_MEDIA_RECORDER_HANDLER_H_
#define CONTENT_RENDERER_MEDIA_MEDIA_RECORDER_HANDLER_H_

#include <memory>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/strings/string_piece.h"
#include "base/threading/thread_checker.h"
#include "content/common/content_export.h"
#include "content/renderer/media/video_track_recorder.h"
#include "third_party/WebKit/public/platform/WebMediaRecorderHandler.h"
#include "third_party/WebKit/public/platform/WebMediaStream.h"

namespace blink {
class WebMediaRecorderHandlerClient;
class WebString;
} // namespace blink

namespace media {
class AudioBus;
class AudioParameters;
class VideoFrame;
class WebmMuxer;
} // namespace media

namespace content {

class AudioTrackRecorder;

// MediaRecorderHandler orchestrates the creation, lifetime management and
// mapping between:
// - MediaStreamTrack(s) providing data,
// - {Audio,Video}TrackRecorders encoding that data,
// - a WebmMuxer class multiplexing encoded data into a WebM container, and
// - a single recorder client receiving this contained data.
// All methods are called on the same thread as construction and destruction,
// i.e. the Main Render thread. (Note that a BindToCurrentLoop is used to
// guarantee this, since VideoTrackRecorder sends back frames on IO thread.)
class CONTENT_EXPORT MediaRecorderHandler final
    : public NON_EXPORTED_BASE(blink::WebMediaRecorderHandler) {
public:
    MediaRecorderHandler();
    ~MediaRecorderHandler() override;

    // blink::WebMediaRecorderHandler.
    bool canSupportMimeType(const blink::WebString& web_type,
        const blink::WebString& web_codecs) override;
    bool initialize(blink::WebMediaRecorderHandlerClient* client,
        const blink::WebMediaStream& media_stream,
        const blink::WebString& type,
        const blink::WebString& codecs,
        int32_t audio_bits_per_second,
        int32_t video_bits_per_second) override;
    bool start(int timeslice) override;
    void stop() override;
    void pause() override;
    void resume() override;

private:
    friend class MediaRecorderHandlerTest;

    void OnEncodedVideo(const media::WebmMuxer::VideoParameters& params,
        std::unique_ptr<std::string> encoded_data,
        base::TimeTicks timestamp,
        bool is_key_frame);
    void OnEncodedAudio(const media::AudioParameters& params,
        std::unique_ptr<std::string> encoded_data,
        base::TimeTicks timestamp);
    void WriteData(base::StringPiece data);

    void OnVideoFrameForTesting(const scoped_refptr<media::VideoFrame>& frame,
        const base::TimeTicks& timestamp);
    void OnAudioBusForTesting(const media::AudioBus& audio_bus,
        const base::TimeTicks& timestamp);
    void SetAudioFormatForTesting(const media::AudioParameters& params);

    // Bound to the main render thread.
    base::ThreadChecker main_render_thread_checker_;

    // Sanitized video and audio bitrate settings passed on initialize().
    int32_t video_bits_per_second_;
    int32_t audio_bits_per_second_;

    // Video Codec, VP8 is used by default.
    VideoTrackRecorder::CodecId codec_id_;

    // |client_| has no notion of time, thus may configure us via start(timeslice)
    // to notify it after a certain |timeslice_| has passed. We use a moving
    // |slice_origin_timestamp_| to track those time chunks.
    base::TimeDelta timeslice_;
    base::TimeTicks slice_origin_timestamp_;

    bool recording_;
    blink::WebMediaStream media_stream_; // The MediaStream being recorded.

    // |client_| is a weak pointer, and is valid for the lifetime of this object.
    blink::WebMediaRecorderHandlerClient* client_;

    std::vector<std::unique_ptr<VideoTrackRecorder>> video_recorders_;
    std::vector<std::unique_ptr<AudioTrackRecorder>> audio_recorders_;

    // Worker class doing the actual Webm Muxing work.
    std::unique_ptr<media::WebmMuxer> webm_muxer_;

    base::WeakPtrFactory<MediaRecorderHandler> weak_factory_;

    DISALLOW_COPY_AND_ASSIGN(MediaRecorderHandler);
};

} // namespace content
#endif // CONTENT_RENDERER_MEDIA_MEDIA_RECORDER_HANDLER_H_
